Philovenator
Philovenator ("love of the hunt") is an extinct genus of troodontid paravian dinosaur from the Campanian of Inner Mongolia, China. In 1988, in the context of the Canada-China Dinosaur Project, Canadian-Chinese paleontological expedition went in Mongolia. One of the many fossils they discovered, was a hind leg of a small theropod from the family of Troodontidae, which in 1994 Philip John Currie described and assigned to Saurornithoides. In 2011 Linhevenator was discovered in the same area, which raised questions wheather the hind limb is actually from the second species. Further studies determined that the leg belongs to a third, new species – Philovenator. The partial troodontid hindlimb IVPP V 10597 was originally described as a juvenile Sauronithoides mongoliensis. The present study reconsiders the taxonomic placement of this interesting specimen, given the significant advances in understanding of the Troodontidae that have taken place since it was first described. Morphological comparison and numerical phylogenetic analyses indicate that V 10597 is more closely related to the sympatric Linhevenator tani than to Sauronithoides mongoliensis, raising the possibility that V 10597 might be juvenile L. tani. However, V 10597 differs significantly from other troodontids, including L. tani, in numerous hindlimb features and particularly in the proportions of various hindlimb elements. These differences are likely to be taxonomic, and suggest that V 10597 represents a new troodontid. Furthermore, histological analysis indicates that V 10597 is unlikely to be juvenile of L. tani or any other large troodontid. Based on the available morphological and histological information, we propose the erection of a new taxon, Philovenator curriei gen. et sp. nov., based on V 10597. This new find increases the known taxonomic diversity and morphological disparity of Late Cretaceous troodontids. In 2012, the type species Philovenator curriei was described and named by Xu Xing, Zhao Qi, Corwin Sullivan, Tang Qingwei, Martin Sander and Ma Qingyu. The genus includes (as many Chinese dinosaurs do) a pun – Philo refers to Curries name Phil. It is also an ancient Greek, philo, which means love and Latin venator, which means hunter. Together it becomes a perfect name for a predator – lover of the hunt. The fossil consists of a virtually complete hind limb. The fibula and tibia are a bit damaged and the fossil lacks the claw of the first toe and the penultimate phalanx and the claw of the third toe. The specimen is a young animal as Currie in 1994 determined, but the 2012 study concluded, that despite the small size the animal was almost grown, one of the reasons to be regarded as a separate taxon. Growth lines in the femur indicated an age of at least one year. The holotype of Philovenator is fairly small, with an estimated length of between fifty and seventy centimeters and a weight of nine hundred grams. The femur has a length of nine inches. The descriptors were able to establish some distinguishing characteristics. The femur has a little above the lower end at the inner side of a striking projection. The tibia has a plate-shaped front upper iliac cnemialis that protrudes far forward. The condyles of the hock and the leg from front to back calacaneum have measured large width and are separated by a deep and narrow pit. The midfoot is the ankle bones fused into a tarsometatarsus very long and slender one-quarter longer than the femur and twenty-two times as long as wide. Of the tarsometatarsus is the width of the middle part of the shaft is measured from front to rear is greater than measured transversely. The fourth metatarsal bone at the back has a raised edge that almost covers the entire shaft and about as wide as the shaft of this element. At the top of the femur, the greater trochanter and lesser trochanter fused into a single comb that is very wide and above the level of the femoral head protrudes, separated from it by a quarry. On the back is a deep posterior trochanter. Philovenator is placed in the Troodontidae family as the sister species of Linhevenator by the descriptors. Scientific classification Kingdom: Animalia Phylum: Chordata Class: Reptilia Superorder: Dinosauria Suborder: Theropoda Family: Troodontidae Genus: Philovenator Xu et al., 2012 Type species: Philovenator curriei Xu et al., 2012 Category:Dinosaurs of Asia Category:Cretaceous dinosaurs Category:Carnivores Category:Troodontids Category:Small Carnivores Category:Fossil taxa described in 2012